}
      } while ((byte1 = bytes[index++]) >= 0);

      if (byte1 < (byte) 0xE0) {
        // Two-byte form.
        if (index == end) {
          return false;
        }
        // Simultaneously check for illegal trailing-byte in leading position
        // and overlong 2-byte form.
        if (byte1 < (byte) 0xC2 || bytes[index++] > (byte) 0xBF) {
          return false;
        }

        }
      } while ((byte1 = bytes[index++]) >= 0);

      if (byte1 < (byte) 0xE0) {
        // Two-byte form.
        if (index == end) {
          return false;
        }
        // Simultaneously check for illegal trailing-byte in leading position
        // and overlong 2-byte form.
        if (byte1 < (byte) 0xC2 || bytes[index++] > (byte) 0xBF) {
          return false;
        }